Chelsea defender Reece James is set for a spell on the sidelines following a hamstring injury sustained in training.
Speaking in his pre-West Ham press conference, Blues boss Mauricio Pochettino confirmed: "It is a sad moment because he’s (James) our captain and he was so excited to be our captain and he was full of energy.
"We are going to assess him day by day. For sure he wants to be again with the team as soon as possible and for sure he’s going to become stronger than he was, because with all the effort of the club we are going to help him to become stronger than before."
James played was taken off in the 76th minute of last weekend's 1-1 draw with Chelsea, although it was later revealed that it wasn't due to injury.
"It’s a hamstring injury. It’s not about a few days, maybe a few weeks," Pochettino continued.
"The good thing is it’s not a big issue, but the most important thing now is to work really hard to try to anticipate problems and to be sure that when he starts to play again he is fully fit and stronger than he was before.
"That is the most important thing. That is why we are going to assess him day by day and try to make the plan every day."
Earlier, the club had confirmed that James was 'starting rehabilitation having undergone assessments on an injury sustained in training this week'.
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